It may be all about a caffeine hit in the morning, but Starbucks is now expanding the sale of alcohol to thousands of its stores across the US to help you unwind at the end of the day, as it looks to boost sales after the morning rush.

The coffee shop chain started selling alcohol in October 2010 at its Seattle store and rolled it out further to another 25 locations in January 2012, including Chicago, Los Angeles and Atlanta.

It will now expand the sale of alcohol, which is only available after 4pm and includes beer and wine, to thousands of its stores across the US over the next few years.

“We’ve tested it long enough in enough markets — this is a program that works,” Troy Alstead, chief operating officer, said.

“As we bring the evening program to stores, there’s a meaningful increase in sales during that time of the day.”

However, Alstead said the sale of alcohol would not work in all Starbucks cafes and noted that they have seen success in some urban areas, near other restaurants and theatres, where people are out at night.

Starbucks - which counts about 11,000 stores in the US - has been focused on selling more non-coffee items, such as alcohol, juice, Teavana tea and food, to stoke US growth.

The company, which announced a long-term plan to almost double its market value to $100 billion earlier this week, is also expanding and improving its rewards program and mobile applications.

Earlier this month, Starbucks said it would soon test a way for customers to order items ahead of time with their smartphones.